【摘要】 目的:采用一次性AICAR注射动物模型,观察AMPK活性变化对Akt、FoxO磷酸化的影响,探讨骨骼肌蛋白质的降解机制。方法:采用同位素技术测定腓肠肌中AMPK活性变化;采用Western blot方法,测定腓肠肌中Akt/FoxO3a总蛋白含量及其磷酸化变化;采用实时荧光定量PCR方法,测定腓肠肌MAFbx mRNA和MuRF-1 mRNA基因表达。结果:AICAR注射后1、2、7 h,AMPK活性与对照组相比升高(P<0.05或P<0.01);AICAR注射后1、2、7 h,Akt磷酸化水平下降(P<0.05或P<0.01),分别是对照组的0.26倍、0.42倍、0.85倍;AICAR注射后1、2 h,FoxO3a磷酸化水平降低(P<0.05),分别是对照组的0.32倍、0.41倍;与对照组相比,AICAR注射后1、2 h,MuRF-1 mRNA和MAFbx mRNA表达量升高(P<0.01),AICAR注射后7 h,MuRF-1 mRNA表达量升高(P<0.05)。结论:AMPK在细胞内可能调节多条信号通路,多种蛋白质降解途径,通过降低Akt磷酸化,活化FoxO,促进泛素蛋白连接酶的表达,降解骨骼肌蛋白质是其中一条途径。更多还原

【Abstract】 Purpose: The purpose of this study was to observe the effect of AMPK activity on Akt and FoxO phosphorylation by using one time AICAR injection animal model,to detect mechanism of protein degradation in skeletal muscle. Methods: AMPK activity was tested by isotope technique,Akt / FoxO3 a protein level and phosphorylation level was measured by Western blotting,MAFbx mRNA and MuRF-1 mRNA were detected by RT-PCR. Results: Compared with control group,the AMPK activity increased 1h,2h,7h after AICAR injection( P < 0. 05),while Akt phosphorylation level decreased( P < 0. 05) which was 0. 26 folds,0. 42 folds and 0. 85 folds of the control group. FoxO3 a phosphorylation level decreased 1h,2h after AICAR injection( P < 0. 05) which was 0. 32 folds,0. 41 folds of the control group. Compared with control group,MuRF-1 mRNA and MAFbx mRNA increased 1h,2h after AICAR injection( P < 0. 01) and MuRF-1 mRNA also increased 7h after AICAR injection( P < 0. 05). Conclusion: AMPK can regulate several signal pathways and multiple protein degradation ways in cells; it can reduce Akt phosphorylation level,active FoxO,promote the expression of ubiquitin-protein ligase,and activation of FoxO,and degrade skeletal muscle protein,which is one signal pathway.更多还原